With winter continuing to have little precipitation and no snow cover, the risk of winter desiccation injury to plants rises. Evergreen trees and shrubs are most susceptible, but lawns and perennials can also be injured.
When there is little snow cover, questions about the need to water during winter arise. While winter watering can be done IF the ground is not frozen and air temperatures are above 40 degrees Fahrenheit, it is important to understand winter watering, even rainfall or melting snow, can also cause plant injury.
For example on lawns and herbaceous perennials, plant crowns absorb moisture and rehydrate. If a rapid drop to freezing temperatures occurs soon after, water taken up by the plant crown freezes. Ice crystals that form then damage or rupture plant cells, and possibly cause death.
This is known as crown hydration injury. It sometimes occurs naturally in late winter when snow is melting, or when an early spring rain is followed quickly by freezing temperatures.
If you would decide to irrigate when soils are not frozen and air temperatures are above 40 degrees, be sure to apply water about mid-day so it has time to percolate into soil before freezing occurs at night. Avoid excess watering so it does not pool around plant stems.
If you decide to do winter watering, evergreen trees and shrubs should be a priority. Evergreens are most susceptible to winter drying and more costly to replace if severely injured or killed.
While all plants continue to lose moisture during winter, evergreens lose more moisture due to their foliage being evergreen. It is not uncommon for evergreens to turn light brown after spring arrives.
For the full story, pick up the February 5 West Point News, or call 372-2461 to subscribe.